1. Field of the Invention
The present invention relates to a semiconductor device, in particular, a bleeder resistance circuit using a thin film resistor, a semiconductor device having the bleeder resistance circuit, and a method of manufacturing the same.
2. Description of the Related Art
Conventionally, a bleeder resistance circuit using a thin film resistor is used in many cases. However, attention is not paid on a potential of a wiring located on the thin film resistor and a potential of a conductor located under the thin film resistor. Thus, the circuits with different arrangements are known. In addition, polysilicon is often used for a thin film resistor material. In the case where an MOS type transistor is combined on a single chip, it is known that the polysilicon with the same film thickness as a gate electrode of the MOS type transistor is used.
However, there is a problem in that a voltage dividing ratio often becomes inaccurate in the conventional bleeder resistance circuit using the thin film resistor. Also, in the case of the conventional bleeder resistance circuit in which the MOS type transistor is combined on a single chip, a change in a resistance value (temperature coefficient of the resistance value) by the temperature of a polysilicon thin film resistor is large in a region with a high sheet resistance value of 1 kiloohm/square or more. Thus, in order to obtain high voltage dividing precision over a wide temperature range, a low sheet resistance value must be set. Therefore, there is a problem in that an area occupied by the bleeder resistance circuit region in which a high resistance value of megaohm order or more is required is expanded as a whole.